Generator layer sensitization through transport layer doping

Abstract

An electrophotographic imaging member including a supporting substrate, an undercoat layer, a charge generating layer comprising photoconductive pigment particles, film forming binder and a charge transport layer formed from a coating solution, the coating solution comprising charge transporting molecules, the charge transporting molecules comprising a major amount of a first charge transport molecule comprising an alkyl derivative of an arylamine and a minor amount of second transport molecule comprising an alkyloxy derivative of an arylamine. the charge generating layer being located between the substrate and the charge transport layer. A process for fabricating this imaging member is also disclosed.

What is claimed is: 
     
       1. An electrophotographic imaging member comprising a flexible supporting substrate,   an undercoat layer,   a charge generating layer comprising benzimidazole perylene photoconductive pigment particles and   poly(4,4'-diphenyl-1,1'-cyclohexane carbonate) film forming binder, and     a charge transport layer formed from a coating solution, the coating solution comprising a polycarbonate film forming binder and   charge transporting molecules, the charge transporting molecules comprising between about 30 percent by weight and about 50 percent by weight alkyl derivative of an arylamine selected from the group consisting of N,N'-bis(alkylphenyl)-[1,1'-biphenyl]-4,4'-diamine wherein the alkyl is selected from the group consisting of methyl, ethyl, propyl and n-butyl, N,N'-diphenyl-N,N'-bis (chlorophenyl)-[1,1'-biphenyl]-4,4'-diamine, N,N'-diphenyl-N,N'-bis(3"-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine and   a second transport molecule comprising between about 5 percent by weight and about 25 percent by weight alkyloxy derivative of an arylamine selected from the group comprising N,N'-diphenyl-N, N'bis[3-methoxyphenyl]-1,1'-biphenyl]-4,4'diamine, N,N'-diphenyl-N,N'bis[4-methoxyphenyl]-1,1'-biphenyl]-4,4'diamine, 4-methoxyphenyldiphenylamine, bis[4-methoxyphenyl]phenylamine, tris[4-methoxyphenyl]amine, and mixtures thereof, the percent by weight being based on the total weight of solids in the coating solution, the charge generating layer being located between the substrate and the charge transport layer.         
     
     
       2. A process for fabricating an electrophotographic imaging member comprising providing a flexible substrate,   forming on the substrate an undercoat layer from a coating solution,   forming a charge generating layer from a coating dispersion comprising benzimidazole perylene photoconductive pigment particles dispersed in   a solution of poly(4,4'-diphenyl-1,1'-cyclohexane carbonate) film forming binder dissolved in a solvent for the binder,     forming a charge transport coating from a coating solution comprising charge transporting molecules, the charge transporting molecules comprising between about 30 percent by weight and about 50 percent by weight alkyl derivative of an arylamine selected from the group consisting of N,N'-bis(alkylphenyl)-[1,1'-biphenyl]-4,4'-diamine wherein the alkyl is selected from the group consisting of methyl, ethyl, propyl and n-butyl, N,N'-diphenyl-N,N'-bis (chlorophenyl)-[1,1'-biphenyl]-4,4'-diamine, N,N'-diphenyl-N,N'-bis(3"-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine and   between about 5 percent by weight and about 25 percent by weight alkyloxy derivative of an arylamine selected from the group comprising N,N'-diphenyl-N,N'bis[3-methoxyphenyl]-1,1'-biphenyl]-4,4'diamine, N,N'-diphenyl-N,N'bis[4-methoxyphenyl]-1,1'-biphenyl]-4,4'diamine, 4-methoxyphenyldiphenylamine, bis[4-methoxyphenyl]phenylamine, tris[4-methoxyphenyl]amine, and mixtures thereof, the percent by weight being based on the total weight of solids in the coating solution,     a polycarbonate film forming binder,   solvent for the binder, and     drying the coating to form a charge transport layer overlying the charge generating layer.